The invention relates to the technical field of vacuum electronics, and provides a miniaturized non-radioactive electron source with a controllable emission current. The miniaturized non-radioactive electron source mainly comprises an acceleration voltage source, an ampere meter, an extraction voltage source, a filament heating current source, filaments, an extraction grid, an acceleration electrode, a silicon nitride film and a vacuum cavity, wherein the extraction grid is positioned in a position in front of the filaments, having a distance of 1mm from the filaments, in the vacuum cavity; the acceleration electrode is arranged at the other end of the vacuum cavity; the silicon nitride film is attached to a central opening of the acceleration electrode outside the vacuum cavity; by virtue of the acceleration voltage source, electrons emitted from the filaments are accelerated to obtain kinetic energy; by adjusting the extraction voltage source, focusing or defocusing of the electron beams in the vacuum cavity can be controlled; the space between the extraction grid and the acceleration electrode is an acceleration region with a length of 5mm; the current can reach 0-300mA when the filaments are in use; an electron extraction electric field between the filaments and the extraction grid is independent from an acceleration electric field, so that electron emission can be controlled by adjusting the current of the filaments and the extraction electric field; and the silicon nitride film is 1*1mm<2> in area and 250nm in thickness.